SHARC resembles a surfboard being pulled by a
submerged set of venetian blinds. Like buoyancy gliders, its totally silent propulsion mechanism makes it an
excellent host platform for a wide variety of acoustic
sensors and towed arrays.

SHARC can conduct maritime interdiction operations and ASW, such as “trip-wire” detection of drug-running self-propelled semi-submersibles and fully
submersibles, and can serve as a communications relay
for other sensors on or below the surface.

“SHARC’s very long endurance and low observability make it an ideal platform to covertly host mission-specific payloads and provide persistent communication gateway services to a variety of offboard sensors,
manned and unmanned craft,” according to Liquid
Robotics Principal Technologist Scott Willcox.

SHARC also can deploy distributed littoral battlespace
sensor arrays and serve as a communications gateway.

Liquid Robotics has designed a system to allow a
guided-missile submarine to carry up to 16 SHARCs in
a single missile tube, launching the SHARCs while submerged and underway. Such a capability could allow a
network of SHARC USVs to be employed as an acoustic
tripwire that can alert the submarine when one of them
detects a target.

“The SHARC USV has demonstrated mission range and
persistence that is unmatched by any other unmanned
system. The unique wave-propulsion system that enables
this long endurance — up to one year of continuous operation has been demonstrated — is also a simple, purely
mechanical mechanism. This means that the SHARC USV
is both highly reliable and more affordable,” Willcox said.

The SHARC has successfully been remotely controlled
during a recent demonstration from the Navy’s Glider
Operations Center at the Stennis Space Center.

Recoverable by Submarine

Saab’s AUV62 UUV is like a torpedo that can be launched
and recovered by a submarine. The sub can launch the
AUV and stand clear to a safer area, or go conduct another mission and return later.

The neutrally buoyant, modular AUV62 UUV comes
in several different configurations, such as the AUV62
mobile acoustic target for ASW training or system calibration — it has a “tail” that makes the target look realistic
in size — or AUV62 MR, used for mine reconnaissance.

“The system can be shipped and brought aboard in
a container, and launched by ship, submarine or from
the shore,” said Carl-Marcus Remén, marketing and
sales manager with Saab Underwater Systems in
Motola, Sweden.

When launched from a submarine, the AUV62 can be
recovered using the Saab SUBROV (submarine-based
remotely operative vehicle), a tethered system that also

LIQUID ROBOTICSThe Sensor Hosting Autonomous Remote Craft, orSHARC, is being tested by the Navy. It can conduct mar-itime interdiction and anti-submarine warfare operations,and serve as a communications relay for other sensors onor below the surface.

can be launched and recovered by a submarine. The
SUBROV can be tube launched, and the sub can catch
and recover the AUV62 in an open torpedo tube, and
then return to its original tube. Then both the SUBROV
and AUV62 can be removed and stowed within the boat
so the tubes can be loaded with torpedoes.

The U.S. Navy developed the AN/BLQ- 11 Long-term
Mine Reconnaissance System for launch and recovery
from the 688-class submarine torpedo tubes. Its vehicle
endurance was demonstrated at greater than 40 hours.

“Other launch and recovery methods were also
demonstrated. Surface ship launches were accomplished
using an A-frame crane or Telescoping Torpedo Launcher.
Surface ship recoveries were accomplished using an A-frame crane. Helo recoveries were demonstrated using a
MK- 30 cage,” said Monica McCoy, a spokeswoman for
Naval Sea Systems Command.

Aboard the submarine, the system’s vehicles,
retrieval system and other gear took up a considerable
amount of space that could otherwise carry torpedos,
and the system and its lithium thionyl chloride batteries became prohibitively expensive. Boeing was the
prime contractor. The program was canceled in 2010.

According to Remén, “Saab’s Double Eagle SAROVis a semi-autonomous ROV that can shift into an AUV,a true dual-use function.”The Double Eagle vehicles are used by many naviesfor MCM operations and the new AUV function of itmakes it more agile in the work against sea mines,Remén said.

“The Danish Navy is the first to take this new func-tionality [into] operation, operating the Double Eagle
in an autonomous mode,” he said. “Denmark uses the
Double Eagle in both modes so they can use the same
vehicle for all MCM missions.” ■